Please see further update from QuoVadis on the OU field Issue:
Retiring the OU field for public TLS/SSL
QuoVadis will turn off the Organizational Unit (OU) field for all new public TLS/SSL certificates starting on August 31, 2020 at 00:59. This will affect new, reissued, and renewed certificates. Existing certificates with OUs are not affected (and do not require revocation or replacement).
Our certificate authority, QuoVadis, will start to restrict what can and cannot be entered in the 'OU' field (Organization Unit) for certificate requests. The 'OU' field, if required, is designed for divisions and departments within the organisation it is not mandatory and can be left blank.